Apparatus for the control of highway crossing signals



March 24, 1936. B. LAZICH A 2,035,169

APPARATUS FOR THE CONTROL OF HIGHWAY CROSSING'SIGNALS Original Filed March 31, 1933 INVENTQR Branko Lazzclz HIS A TTORNEY Patented Mar. 24, 1936 PATENT QF'FICE.

APPARATUS FOR THE CONTROL OF HIGHWAY CROSSING SIGNALS Branko Lazich, Edgewood, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application March 31,

1933, Serial No. 663,729

Renewed August 30, 1935 23 Claims.

My invention relates to apparatus for the control of highway crossing signals, and particularly to apparatus for providing a uniform period of warning at the highway.

An object of my invention is the provision of apparatus controlled by a train approaching a highway intersection for measuring the speed of the train, and for also determining the acceleration or deceleration of the train. The starting of the operation of the highway signal is controlled in accordance with the measured speed and determined condition of acceleration or deceleration in such a manner that substantially an equal interval of operation of the highway signal before the train reaches the highway is obtained for all trains. A further object of my invention is the provision of apparatus to assure operation of the highway crossing signal in case of a following train entering the approach or measuring track section before the first train has passed the crossing, and to prevent operation of the apparatus in the case of reverse running. A still further object of my invention is the provision of apparatus to check the operating condition of the speed measuring devices. Other objects and features of my invention will appear as the specification progresses.

I will describe one form of apparatus embodying my invention, and will then point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic view of one form of apparatus embodying m invention.

Referring to the drawing, the reference characters I and l designate trafilc rails over which trathc normally moves in the direction indicated by an arrow and which are intersected by a highway H shown at the right-hand end of the drawing. At the highway intersection there is located a highway crossing signal S. The signal S is.

indicated on the drawing conventionally as a combined audible and flashing light highway crossing signal. It will be understood, however, that my invention is not limited to any specific form of highway signals and any of the standard signals may be used. The signal S in the drawing will serve to indicate a highway signal normaliy inactive, and which is rendered active to display a warning to highway users whenever a train approaches the intersection. The operation of the signal S is governed by a mechanism indicated by the reference character M which mechanism is effective to render the signal S active in response to current supplied thereto.

The trafic rails I and l are divided by the usual insulated rail joints into four track sec-. tions AB, BC, CD and D--E, which track sections are traversed successively by a. train approaching the highway 1-1 when moving in the normal direction of traffic. is provided with a track circuit comprising a track battery 3, and a track relay R with an exponent designating its location. Interposed between the track relay R and rail I for the track section AB is a front contact 4 of the track relay R and in like manner a front contact 5 of relay R is included in the connection of the track relay R with the rail l of the section BC. The function of these front contacts will become apparent as the description proceeds. For the purpose of this description, I shall speak of the sections AB and BC as measuring sections, the section CD as an operating section, and the section DE as a positive operating section. As will appear hereinafter, the speed of a train as it traverses the measuring sections A--B and BC is measured, and the acceleration or deceleration of the train is determined. The highway crossing signal S is set into operation as the train traverses the operating section CD in accordance with the measured speed and the condition of acceleration or deceleration, the time of starting of the operation of the signal being made such as to insure substantially an equal interval of operation before the train reaches the highway for all trains. Positive operation of the highway signal S takes place during the time a train occu-. pies the track section DE irrespective of whether the train is moving or not.

In order to more easily understand the opertion of the apparatus of my invention, I shall assume the maximum speed for all trainsto be miles per hour, and that substantially 20 seconds exhibit of the highway crossing signal will be obtained before the train reaches the highway. A train travelling at 90 miles per hour will move approximately 2640 feet in 20 seconds, and consequently, the combined length of sections CD and DE is made 2640 feet in length. 'Preferably the section D-E is made short, say, 300 feet in length, and hence the operating section CD is 2340 feet in length. For reasons to appear hereinafter the two measuring sections AB and BC are preferably equal in length and their combined length equal to the combined length of sections CD and DE. That is to say, the measuring sections will be each 1320 feet in length. It will be understood, of course, that my invention is not limited to the above lengths for the track sections, and the length of these sev- Each track section eral sections will be arranged to suit each indi vidual location, and to suit different maximum speeds and different intervals for operating the highway crossing signal.

As here shown the speed measuring device comprisesa shaft 6 shown schematically by a dotted line, and on which are rigidly mounted three circuit controlling cams l, 8 and 9. Shaft 6 is driven by a motor M through the medium of a suitable train of gears designated by the reference characters I0 and II. The shaft 6 and the cams I, 8 and 9 normally occupy the postion in which they are illustrated in the drawing, and are arranged to be at times moved away from this normal position in a clockwise direction toward a reverse position by the rotation of the motor M in one direction, the full reverse position being a little less than one revolution. At other times they are restored to the normal position by reversing the direction of rotation of motor M A centrifuge N is operatively connected with the motor M and this centrifuge governs a circuit controlling contact C6 in such a manner that the. contact C6 rests in engagement with contacts l2 and 13 as long as the motor M is not operated, and is raised into engagement with contacts l4 and [5 when the motor is rotating at a speed which exceeds a predetermined value. The centrifuge N is provided to check the normal position and operation of the motor M as will appear hereinafter.

Associated with the speed measuring device is a relay SR which is slightly slow releasing in character. Relay SR is normally energized over a circuit extending from the terminal X of a convenient source of current such as a battery not shown, through front contact N5 of the track relay R", a circuit controller C8 operated by the cam 1, wire l1, winding of relay SR and to the opposite terminal Y of the same source of current. Relay SR governs the operation of the highway crossing signal S as will later appear, and it is made slightly slow releasing to bridge the time interval required for the motor M to reverse its direction of rotation.

The circuit controlling cam l is adapted to control five circuit controllers C2, C3, C8, C9 and CH]. Circuit controllers C8, C9 and Cl!) are normally closed and are opened only after the cam has been operated in a clockwise direction to the reverse position, that is, approximately a full revolution, where a member l8 drops into the depression IS on the cam 1. Circuit controller C2 is normally closed and is opened immediately after cam is moved in a clockwise direction from the normal position and a member 20 is raised out of the depression l9. The controller C3 is normally open, and is closed as member 20 is lifted out of the depression IS. The cam 9 is provided with a contact segment 23 of a predetermined length and which in the normal position of the cam engages the contact member 24 of a controller C4. The parts are so proportioned and adjusted that the contact member 24 remains in engagement with the contact segment 23 for approximately 20 seconds of operation of the cam 9 in the clockwise direction. The cam 8 is provided with a contact segment 2! which normally engages the contact member 22 of a controller C5. The contact segment 2| is preferably made equal in length to the contact segment 23 on the cam 9. The function of these controllers C2, C3, C4, C5, C8,

C9 and CID will appear when the operation of the system is described.

The acceleration-deceleration measuring device comprises a shaft 25 indicated in the drawing by a dotted line, and on which are rigidly mounted a cam 26 and a contactor 21. The cam 26 and contactor 21 normally occupy the position illustrated in the drawing and are adapted to be driven at times away from that position either in the clockwise direction or in the counter-clockwise direction by a constant speed motor M driving the shaft 25 through the medium of a train of gears indicated by the reference characters 28 and 29. At times the motor M is rotated in a direction to drive the shaft 25 in a counter-clockwise direction, at other times the motor M is rotated in the opposite direction and the shaft 25 is driven in a clockwise direction, and at still other times the motor M is operated in a direction that brings the cam 26 and contactor 21 to their normal position. The cam 26 is adapted to operate a pole-changing circuit controller CI in such a manner that as the shaft 25 is rotated counterclockwise from the normal position, an operating member 14 drops into a depression 15 and the back contacts 53 and 54 of controller C! are closed. At such time as the cam 25 is operated clockwise from the normal position, the member 14 is lifted by a raised portion 16 and the front contacts 5| and 52 of controller Cl are closed. In the normal position of the cam 23 all contacts of controller Cl are open. One end of the contactor 21 is adapted to make contact with a contact segment 30, and its other end normally makes contact with a centrally located contact button 3| of a variable resistance unit comprising two resistors R and R Resistors R. and R. are preferably arranged in steps and are provided with contact buttons with which the contactor 2'! will successively engage as it is rotated from the normal position. As will appear later, the centrally located button 3! constitutes what I shall call a constant speed point and which point is here identified by the reference character CP. The resistor R to the right of the constant speed point CP constitutes a compensating resistance for deceleration, and the resistor R to the left of the point CP constitutes a compensating resistance for acceleration. It follows, that when the contactor 21 rests on the contact button 3| at the constant speed point CP, the full resistor R is in circuit between the contact segment 39 and a terminal 65. When the shaft 25 and hence contactor 21 are rotated counterclockwise, the contactor 21 is moved along the successive contact buttons of resistor R and the successive portions of resistor R are added to the resistor R in the connection between the segment 30 and the terminal 65. When the shaft 25 is rotated clockwise, the contactor 21 is moved along the successive contact buttons of resistor R and portions of the resistor R are cut out of circuit, making the resistance between the contact segment 30 and the terminal 65 something less than the full resistance of resistor R As will later appear, a third resistor R is associated with the two resistors R, and R and the resistance of the resistor R is preferably made equal to that of the full resistance of the resistor R A stick relay R is included in the equipment and this relay B is provided with an energizing circuit which can be traced from the terminal X of the current source through wire 82, front contact 32 of track relay R wire 33, controller C2,

wire 34, winding of relay R wire 35, front contact 36 of track relay R and to the opposite terminal Y of the current source. A stick circuit for this relay R extends from the terminal X of the current source through controller C9, its own front contact 31, winding of the relay R and thence as before traced to the terminal Y.

Referring to the drawing, the operation of my system can be explained as follows: As long as no train occupies any of the track sections, the track relays R R R and R are all picked up and both motors M and M are inactive, and both the speed measuring device and the acceleration-deceleration measuring device are in the normal position, that is, the position shown in the drawing. The mechanism M is also dee-nergized and signal S is inactive. A train approaching the highway H from the left first enters the track section AB and shunts the track relay R As relay R is released, current is supplied to both motors M and M and these motors rendered active. Tobe explicit, the field winding MB! of motor M now receives current from the X terminal of the source of current over wire 82, back contact 38 of relay R wire 39, field winding MFI, a second back contact 40 of relay R wires 4| and 42, front contact 43 of the stick relay R and to the terminal Y of the current source. The armature 44 of motor M is supplied with current from the terminal X of the current source over wire 83, front contact 45 of track relay R front contact 46 of track relay R back contact 4! of track relay R controller CID, armature 44, back contact 48 of relay R front contact 49 of relay R front contact 50 of relay R wire 42 and front contact 43 of relay R to the opposite terminal Y of the current source. The energization of the armature 44 by this circuit is such as to cause the motor M to be rotated in a direction that rotates the shaft 25 in a counter-clockwise direction and at a predetermined rate of speed. Consequently, contactor 21 is now moved to successively cut in resistance steps of the compensating resistor R After a slight movement of shaft 25, the cam 26 will shift the controller CI to close the back contacts 53 and 54, the purpose of which will be later pointed out.

The field winding MP2 of motor M is now energized by current supplied from the terminal X of the current source over wire 82, back contact 38 of relay R wires 39 and 55, field winding MFZ, wire 61, resistor R front contact 56 of relay R wire 51, back contact 40 of relay R wires 4| and 42 and thence over front contact 43 of relay R to the terminal Y. The armature 58 of motor M is supplied with current from battery terminal X overfront contact l6 of relay R controller 08, wires I! and 59, back contact 60 of relay R armature 58, back contact 6| of relay R front contact 62 of relay R and thence over the front contact 43 of relay R to the terminal Y. The energization of the armature 58 by this circuit just traced is such as to cause the motor M to rotate in a direction to drive the shaft 5 in the clockwise direction at a predetermined rate of speed. It follows that the cams l, 8 and 9 are rotated in a clockwise direction, and the centrifuge N is operated to raise the contact C6 out of engagement with the contacts I2 and I3 but not far enough to engage the contacts I5 and I4.

It is clear from the foregoing description that as long as the train occupies the section AB, the acceleration-deceleration measuring device is driven in a counter-clockwise direction at a predetermined rate, and that the speed measuring device is driven in a clockwise direction at a predetermined rate. The angular distance the contactor 21 of the acceleration-deceleration device, and the cams i, 8 and 9 of the speed measuring device are rotated will depend upon the time it takes the train to pass over the section AB.

As the train advances into the second measuring section BC, the track relay B is shunted and that relay is released. The opening of the front contact 4 of relay R causes relay R to be held deenergized as long as the train occupies the section B-C. With relay R held down, the previously traced circuit for the field winding MB! of motor M remains closed at the back contacts 38 and 4B the same as when the train oecupied the section AB. Track relaylt upon releasing opens the front contacts 45 and 50 and closes the back contacts 63 and 4 to pole change the armature circuit for the motor M as will be readily understood by an inspection of the .drawing. Reversing the direction of the current flow in the armature 44 of the motor M reverses the rotation of that motor and the shaft 25 of the acceleration-deceleration measuring device is now driven in a clockwise direction, the rate of rotation remaining the same as the rate at which it was rotated in the counter-clockwise direction. As previously stated, the track section AB is made the same length as the section B-C and since the speed of motor M is the same in both directions of rotation, it is clear that if a train travels over both sections AB and BC at a constant speed, the contactor 21 travels in the clockwise direction while the train passes over section BC, the same angular distance as it travelled in the counter-clockwise direction while the train is passing oversection AB, and it is returned to the constant speed point CP as the train reaches the outgoing end of section BC. If, however, the train is not running at a constant speed, but is accelerating, contactor 27 would be driven for a longer time in the counter-clockwise direction during the time the train was passing over section AB, than it is driven in the clock wise direction while the train is passing over the section BC, and, consequently, contactor 2'! would be at some point to the left of the constant speed point CP when the train reaches the outgoing end of section BC. As a result, a certain portion of resistor R is inserted with resistor R in the connection between the terminal 55 and the segment 33. On the other hand, if the train is slowing down, the contactor 2'! would be driven in the clockwise direction for a longer period while the train is passing over section BC, than it would be driven in the counter clockwise direction while the train is passing over section AB and contactor 21 is at some point to the right of the constant speed point CP when the train reaches the outgoing end of section B--C. Under this condition, a certain portion of resistor R would be cut out of the connection between the terminal 65 and the segment 3E1. It follows, therefore, that the resistance between the terminal 65 and the segment 30 is in accordance with the acceleration or deceleration of the train, being equal to that of resistor R. when the speed is constant and there is neither acceleration nor deceleration, being equal to resistor R plus a corresponding portion of resistor R when the train is accelerating, and being equal to a corresponding portion of resistor R only when the train is decelerating.

The shunting of the track relay R causes no change in the circuit for the field winding MFZ, or in the circuit for the armature 5B and hence, motor M continues to drive the shaft 6 in the clockwise direction while the train occupies the section B-C the same as when in the track section AB. If a train is travelling at the maximum speed of 90 miles per hour, it will require approximately 20 seconds for it to pass over the 2,640 feet of the two measuring sections, and consequently, the cam 9 will not be rotated far enough to open the controller 04 before the train reaches the outgoing end of section BC. In the event the train passes over the measuring section at some speed less than the maximum speed, say for example, 60 miles per hour, it would consume approximately 30 seconds before it reaches the exit end of the section BC and the cam 9 would have rotated in the clockwise direction for a corresponding period of time and the controller C4 would have been opened for approximately the last 10 seconds of this period. In the event the speed of the train was only 30 miles per hour, it would consume approximately 60 seconds in passing over the twomeasuring sections and controller C4 would have been open for approximately the last 40 seconds of that period. It follows that the angular distance of rotation of the cams l, 8 and 9 is in accordance with the speed of the train in the measuring sections, and the length of time the controller 04 is open during this operation is inversely proportional to the average speed of the train.

To sum up thus far, when a train maintains substantially a constant speed as it travels over the two measuring sections AB and 13-0, the contactor 2'! is set at the constant speed point CP; if the train is accelerating, contactor 2? is set at a corresponding point to the left of the constant speed point CP inserting a portion of resistor R with resistor R in the connection between the terminal 65 and the segment 38; and if the train is decelerating, contactor 21 is set at a corresponding point to the right of the constant speed point C]? and a portion of resistor R is cut out of the connection between terminal 65 and the segment 30. In all cases the speed measuring device is constantly driven in a clockwise direction during the entire time the train is passing over the two measuring sections, with the result that the angular distance that the cam 9 has been rotated corresponds to the average speed of the train.

The train upon entering the operating section C--D shunts the track relay R and that relay is released. The front contact 5 in the circuit for relay R is now open and hence both track relays R and R remain down as long as the track relay R is deenergized. Opening of the front contacts 46 and 49 of relay RP, removes current from the armature circuit of motor M and operation of the acceleration-deceleration measuring device is stopped. The result is that contactor 21 is stopped as soon as the train enters the operating section C'-D, and is left in the position to which it has been operated in the manner described above. Opening of the front contact 56 of relay R, and the closing of the back contact 66 transfers the circuit for the field winding MP2 of motor M from the resistor R to the circuit through the resistors R and R The circuit for the field Winding MP2 now includes battery terminal X, wire 82, back contact 38 of relay R wires 39 and 55, field winding MF2, wire 61, terminal 65, resistors R and R in accordance with the position of contactor 2?, segment 30, back contact 66, wire 51, back contact 46, wires 4| and 42 and front contact 43 of relay R to the terminal Y. As relay R is released, the opening of the front contacts I6 and 62 and the closing of the back contacts 68 and 69 pole changes the armature circuit for motor M and hence the direction of motor M is reversed. To be explicit, the circuit for the armature 58 now extends from the terminal X over back contacts 68 and 6|, armature 58, back contact 60, wire 59, controller C3 which was closed as soon as cam 7 was moved from its normal position, wire 10, back contact 69 and the front contact 43 of relay R to the terminal Y. The rotation of the motor M having been thus reversed, the shaft 6 is driven in a counter-clockwise direction from the point to which it has been advanced while the train occupied the measuring sections back toward the normal position and the speed of motor M will be in accordance with the position of the contactor 21. In the case the speed of the train remained constant as it traversed the sections AB and BC and contactor 21 is at the point CP, the full resistance of resistor R is inserted in the circuit for the field winding MFZ, and as this resistance is equal to that of the resistor R the rotation of motor M will be at the same rate for the reverse direction as it was for the normal direction. In the event the train was accelerating and the contactor 21 is set at some point to the left of the constant speed point CP, the resistance in the field circuit is equal to resistor R plus a portion of resistor R. and the energization of the field winding MP2 is correspondingly decreased so that the speed of motor M during its reverse operation is increased proportionally. That is, the increase in the speed of motor M is in direct proportion to the acceleration registered by the contactor 21. In the event the train was slowing down as it traversed the sections AB and B-C, and the contactor 21 is set at some point to the right of the constant speed point OP, the resistance in the circuit to the field winding MF2 is something less than that of resistor R with the result that the energization of the field winding MP2 is increased and the speed of the motor M correspondingly decreased. That is to say, the decrease in the speed of the motor M during its reverse operation is directly proportional to the deceleration of the train.

When relay R was shunted by the train entering the operating section CD, the opening of the front contact l6 removed'energy from the winding of relay SR and that relay released at the end of its slow release period to close its back contact ll As soon as the cam 9 is rotated back toward its normal position, in the manner just described, far enough to bring the contact segment 23 into engagement with the contact member 24, current is supplied to the mechanism M of the highway signal S. This operating circuit extends from the terminal X of the current source over line wire 72, back contact H of relay SR, contact 23-24 of controller C4, line wire 13, mechanism M of signal S and thence to the opposite terminal Y. In the event the train is travelling at the maximum speed of 90 miles per hour and the controller C4 has not been opened, the mechanism M is energized as soon as the relay SR releases and the signal S is displayed substantially the full time required for the train to pass over the operating sections CD and D-E and the 20 seconds operation of the signal before the train reaches the highway H is provided. In the case the trainis travelling at a lower speed than the maximum speed and its speed remains substantially constant throughout the measuring sections, the speed measuring device is restored to its normal position at the same rate as it was rotated away from its normal position and controller C4 is not closed until some time after the train has entered the operating section CD, the delay being such as to provide substantially 20 seconds operation of the signal S for all constant speeds. In the case the train is accelerating as it passes over the measuring sections, the earn 9 is rotated back toward its normal position at a speed sufiioiently increased over the rate at which it was driven away from its normal position as to close the controller C4 soon enough to provide the 20 seconds operation of the signal S before this accelerating train reaches the highway. That is to say, the resistance inserted in the circult to the field winding MF2 by the operation of contactor 21 will so increase the reverse operation of motor M as to compensate for the acceleration of the train. In the case the train is slowing down as it passes over the measuring sections, the contactor 2'! functions to decrease the resistance in the field winding MF2 and the reverse operation of the motor M is slowed down sufficiently as to assure substantially the same 20 seconds operation of the signal S before the train reaches the highway. In other words, when the speed of the train remains substantially constant, the speed measuring device so functions for all speeds as to provide substantially the 20 seconds operation of the highway signal. The acceleration-deceleration measuring device so governs the rate of speed of the speed measuring device during its reverse operation as to compensate for acceleration or deceleration and still assure the same 20 seconds operation of the highway crossing signal.

During the time the train occupies the short track section DE positive operation of the highway signal S is accomplished. When the train enters the section D--E, the relay RP is shunted and its back contact H is closed. The closing of the back contact Tl completes an operating circuit easily traced for supplying current to the mechanism M of the highway signal. It follows that the signal S will be continuously displayed as long as the train occupies the section DE irrespective of whether it is moving or not. As stated above, this section DE is short, and is preferably made only just long enough to assure positive operation of the signal S should a train stop at the highway.

shunting of the track relay R also opens the front contact 35 in the stick circuit for the relay R causing that relay to become deenergized. Relay R upon releasing closes a back contact 18 to complete a shunt path around the back contact 69 of relay R and the front contact 43 of relay R in the armature circuit for the motor M Consequently, the reverse operation of motor M is continued after the train enters the section DE until the speed measuring device has been restored to its full normal position and controller C3 opened by the member 20 dropping into the cam depression [9. The contact segment 2i of the cam B is preferably made of the same length as the contact segment 23 of cam 9. Thus, when the speed measuring device is restored toward its normal position after the train has entered the operating sections, far enough to close the controller C4 and start operation of the highway signal S, the controller C5 is also closed and the motor M is energized to restore the accelerationdeceleration measuring device to its normal position. The circuit for energizing the field winding MFI of motor M remains the same as previously traced except that the connection to the Y terminal of the current source is now over the back contact 69 of relay R and the back contact 7801? relay R instead of over the front contact 43 of relay R Current is now supplied to the armature 44 of motor M over the circuit controllers C5 and C I, the circuit extending from the X terminal of the current source through contact 2l-22 of controller C5, back contact 54 of controller Ci in the event the contactor 21 occupies a position to the left of the constant speed point CP, back contact is of relay RC, back contact 48 of relay R armature 44, controller CID, back contact 41, back contact 80, back contact 53 of controller Cl and to the Y terminal of the current source. The rotation of motor M is now in a direction to drive the contactor 21 clockwise from its position to the left of point CP back to the constant speed point CP at which point the cam 26 lifts the member 14 to its center position to open the controller Cl and remove current from the motor M In the event the contactor 21 oocupied a position to the right of the point CP, the front contacts 5| and 52 of controller Cl are closed and the rotation of motor M is in a direction to drive the contactor 21 in a counter clock wise direction back to the constant speed point CP where the controller Cl is shifted to its center position and motor M deenergized.

In the event a second train should enter the measuring section A-B before the first train has passed the highway H and vacated the track section DE, the stick relay R will not be reenergized when the first train moves out of the section DE. Under this condition, the pickup circuit for relay R is held open at the front contact 32 of track relay R that relay being shunted by the second train occupying the section AB. The front contact 43 of relay R being held open, operation of neither motor M nor M takes place in response to the second train in the measuring section. The operating circuit for the mechanism M is now completed through the back contact 8| of relay R and hence operation of the highway signal S is continued while the second train travels the successive track sections in approaching the highway H.

In the event a train is travelling in the reverse direction, that againstthe normal direction of traffic, and enters the track section DE from the right, the measuring devices remain inactiver Under this condition, the track relay R is first deenergized to open the front contact 36 in the stick circuit for relay R and that relay is released. The front contact 43 of relay R being now open, the circuits for both motors M and M are not completed when the track relays R R and R become deenergized, and hence neith er the speed measuring device nor the acceleration-deceleration measuring device will function while this train travelling in the reverse direction occupies the successivetrack sections.

If for any reason, the motor M fails to operate, the contact member C6 will remain in engagement with the contacts l2 and I3, and the signal S will be operated immediately when the train enters the operating section CD to release the relay SR. The operating circuit now extends from terminal X along wire 12, back contact ll, contact l2l3 of C6, wire 13, mechanism M to the terminal Y. Again, if for any reason the motor M is operated at an abnormally high rate of speed, the contact member C6 will be lifted into engagement with the contacts l4 and I5 and operation of the highway signal S will be immediately started as soon as the relay SR is deenergized.

It should be noted that in the event a train should stop in either of themeasuring sections, the motor M would drive the shaft 6 around to its full reverse position where the depression IQ- of the cam 1 mates with the member l8 and the controllers C8, C9 and C10 are all opened. This operation of the controllers C8 and CIO opens the armature circuit for motors M and M respectively, and the operation of the speed measuring device and of the acceleration-deceleration measuring device is stopped. Controller C9 opens the stick circuit for the relay R and that relay is deenergized and will remain deenergized as long as the speed measuring device occupies this full reverse position. With relay R down, current is supplied to the mechanism M of the highway signal S by the circuit completed at the back contact 8| of relay R When this train proceeds and enters the operating section CD, the shunting of the track relay R will cause the speed measuring device and the acceleration-deceleration measuring device to be restored to their respective normal position in the same manner as described hereinbefore. The relay R will not be reenergized until after the train has passed the highway, and hence the signal S will be operated to warn the highway users.

Although I have herein shown and described only one form of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection; a speed measuring means, and an acceleration-deceleration measuring means and both governed by a train approaching the intersection; and means controlled jointly by the speed measuring means and the acceleration-deceleration means for starting the operation of said signal at substantially the same interval of time before the train reaches the intersection regardless of the speed and condition of acceleration or deceleration of the train.

2. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, a first measuring means governed by a train approaching said intersection and adapted to start the operation of said signal at substantially the same interval of time before the train reaches the intersection regardless of the average speed of the train, and a second measuring means governed by a train approaching the intersection and adapted to control said first measuring means in such a manner as to start the operation of said signal at substantially the same said interval of time before the train reaches the intersection notwithstanding acceleration or deceleration of the train.

3. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, a speed measuring means governed by a train approaching said intersection for measuring the average speed of the train and adapted to start the operation of said signal at substantially the same interval of time before the train reaches the intersection for all measured speeds, and an acceleration-deceleration measuring means governed by a train approaching said intersection for determining the acceleration and deceleration of the train and adapted to control the speed measuring means in such a manner as to start the operation of said signal at substantially the same said interval of time before the train reaches the intersection notwithstanding acceleration or deceleration of the train.

4. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, operating means for setting the signal into operation When a train approaching the intersection reaches a fixed point, a first device to register the speed of the train as it approaches said fixed point, a second device to register the acceleration or deceleration of the train as it approaches said fixed point, and means controlled jointly by said two devices to retain the operating means inefiective to set the signal into operation for a period determined by the registered speed and the registered acceleration or deceleration after the train reaches said fixed point.

'5. In combination, a stretch of railway track intersected by a highway, at highway signal located at the intersection, operating means for setting the signal intooperation when a train approaching the intersection reaches a fixed point, a first device to register the average speed of the train as it approaches said fixed point, a second device to register changes in the speed of the train as it approaches said fixed point, and means controlled jointly by said two devices to retain the operating means ineffective to set the signal into operation for a period which depends upon both the registered speed and the registered change in the speed after the train reaches said fixed point.

6. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, a first device governed by a train approaching the intersection to measure the time interval required for such train to traverse a fixed distance, a second device governed by such train while traversing such fixed distance to register the difference between the time intervals required by the train to traverse the first and the second half of said fixed distance, and means controlled jointly by said two devices for governing the operation of said signal.

'7. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, operating means for setting said signal into operation when a train approaching the intersection reaches a fixed point; a time measuring means to measure the time interval required for a train approaching said fixed point to traverse a fixed distance, and to determine the difference between the time intervals required by the train to traverse the first and the second half of said fixed distance; and means controlled by the time measuring means for delaying the operating means from setting said signal into operation for a period which depends upon both the said measured time interval and the said determined difference in time intervals.

8. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, operating means for setting said signal into operation when a train approaching the intersection reaches a fixed point; a time measuring means to measure the time interval required for a train approaching said fixed point to traverse a fixed distance, and to determine the difference between the two time intervals required by the train to traverse two different given portions of said fixed distance; and means controlled by the time measuring means for delaying the operating means from setting the signal into operation for a period which depends upon both the said-measured time interval and said determined differenc in time intervals.

9. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, operating means for setting said signal into operation when a train approaching the intersection reaches a fixed point; a time measuring means to measure the time interval required for a train approaching said fixed point to traverse a fixed distance, and to determine the difference between the two time intervals required by the train to traverse two diiferent given portions of said fixed distance; means controlled by the time measuring means for delaying the operating means from setting the signal into operation for a period which depends upon both the said measured time interval and said determined difference in time intervals, and means for annulling the period of delay in the event of failure of the time measuring means.

10. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, operating means for setting said signal into operation when a train approaching the intersection reaches a fixed point, a first time measuring means to measure the time interval required for a train approaching said fixed point to traverse a fixed distance, a second time measuring means to determine the diiference between the two time intervals required by the train to traverse two different given portions of said fixed distance, and means controlled jointly by said two time measuring means for delaying the operating means from setting the signal into operation for a period which depends upon both said measured time interval and said determined difference in time intervals.

11. In combination, astretch of railway track including a first and a second track section of .substantially equal lengths, a signaling device,

a time measuring means operated by a train passing through said track sections to register the difference in the time intervals required for a train to traverse said first and said second track sections and thereby determine the acceleration or deceleration of said train, and means controlled by said time measuring means to govern said signaling device in accordance with the determined acceleration or deceleration.

12. In combination, a stretch of railway track including a first and a second track section and each of a predetermined length, a signaling device, a time measuring means operated by a train passing through said track sections to measure the difference in the time intervals required for a train to traverse said first and said second track sections whereby the change in the speed of the train is registered, and means controlled by said time measuring means to govern the signaling device in accordance with the change in the speed of the train.

13. In combination, a stretch of railway track intersected by a highway and divided into a measuring section and an operating section'which a train traverses in the order named as it approaches the intersection, a highway crossing signallocated at the intersection, operating means to start operation of said signal as'a train enters the operating section, a first device to render the operating means ineffective to start operation of the signal for a period varying inversely with the average speed of the train in the measuring section, and a second device to decrease or increase said period in proportion to the increase or decrease in the speedof the train in the measuring section.

14. In combination, a stretch of railway track 7 intersected by a highway and divided into a measuring section and an operating section which a train traverses in the order named as it approaches the intersection, a highway crossing si nal located at the intersection, operating means to start operation of said signal as a train enters the operating section, a first device to render the operating means ineifective to start operation of the signal for a period varying inversely with the average speed-of the train in the measuring section, and a second device to modify said period in proportion to the change in the speed of the train in themeasuring section.

15. In combination, a stretch of railway track intersected by a highway, a highway crossing signal, a first member normally occupying one position, means for moving said first member away from said one position at a constant speed during the time interval required for a train approaching the highway to traverse a fixed distance, a second member normally occupying a given position, means for moving said second member in one direction away from said given position at a constant speed during the time the train travels the first half of said fixed distance and to move said second member in the opposite direction at said constant speed during the time the train travels the second half of said fixed distance, means effective when the train has traversed said fixed distance for restoring said first member to said one position at a speed which de-, pends upon the position to which said second member has previously been moved, and means governed by said first member for controlling said signal.

16. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at said intersection, a member normally occupying one position, a first operating means effective for moving said member away from said one position at a constant speed during the time intervalrequired for a train approaching the intersection to traverse a fixed distance, means to register the change in speed as the train traversed said fixed distance, a second operating means effective when the train has traversed said fixed distance for restoring said member to said one position at a speed which depends upon the registered change in speed, and means governed by said member for setting said signal into operation.

1'7. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at said intersection, a first member normally occupying one position, a first operating means effective for moving said member away from said one position during the time interval required for a train approaching the intersection to traverse a fixed distance, a second member normally occupying a given position, a. second operating means for moving said second member away from said given position in accordance with the change in the speed of the train in travelling said fixed distance, a third operating means efiective when the train has traversed said fixed distance for restoring said first member to said one position in accordance with the position of said second member, means governed by said first member for controlling the operation of the signal, and means effective to restore said second member to said given position after operation of said signal is started.

18. In combination, a stretch of railway track intersected by a highway and divided into a measuring section and an operating section which a train traverses in the order named as it approaches the intersection, a highway crossing signal located at the intersection, operating means to start operation of said signal as a train enters the operating section, a speed measuring device controlled by a train in the measuring section for rendering the operating means ineffective to start the operation of said signal for a period in accordance with the speed of the train, and means including a stick relay eifective to maintain operation of the signal irrespective of the speed measuring device when a second train enters the measuring section before a preceding train has vacated the operating section.

19. In combination, a stretch of, railway track intersected by a highway and divided into a measuring section and an operating section which a train traverses in the order named as it approaches the intersection, a highway signal at the intersection, a speed measuring device controlled by a train in both the measuring and operating sections, an acceleration-deceleration measuring device controlled by the train in the measuring sections, means controlled jointly by said two devices for governing the operation of the signai, and circuit means operative in response to a train as it traverses said operating and measuring sections in moving away from the intersection for rendering both the speed measuring means and the acoeieration-deceleration means inoperative.

20. In combination, a stretch of railway track over which trafiic normally moves in one direction and intersected by a highway, a highway signal located at the intersection, a speed measuring device and an acceleration-deceleration measuring device both controlled by a train as it approaches said intersection in the normal direction of traffic, operating means controlled jointly by said two devices for governing the operation of said signal, and means responsive to a train traveling away from the intersection in a direction reverse to the normal direction of trafiic to render both the speed measuring device and the acceleration-deceleration measuring device ineffective to govern said signal.

21. In'combination, a stretch of railway intersected by a highway, a highway crossing signal located at the intersection, operating means governed by a train for setting the signal into operation when the train reaches a fixed point to the rear of the intersection, a speed measuring means, an acceleration measuring means, means governed by the train approaching the fixed point for operating said speed measuring means and said acceleration measuring means, means controlled by the speed measuring means to render the operating means inefiective to start operation of the signal for a period varying inversely with the measured speed of the train, and means controlled by the acceleration measuring means to correct said period in proportion to the acceleration of the train.

22. In combination, a stretch of railway intersected by a highway, a highway crossing signal located at the intersection, operating means governed by a train for setting the signal into operation when the train reaches a fixed point to the rear of the intersection, a speed measur ing means, an acceleration and deceleration measuring means, means governed by the train approaching the fixed point for operating said speed measuring means and said acceleration and deceleration measuring means, means con trolled by the speed measuring means to render the operating means inefiective to start operation of the signal for a period varying inversely with the measured speed of the train, and means controlled by the acceleration and deceleration measuring means to correct said period in proportion to the acceleration or deceleration of the train.

23. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection, a speed measuring means, an acceleration-deceleration measuring means, means governed by a train approaching the intersection for operating said speed measuring means and said accelerationdeceleration measuring means, operating means controlled jointly by the train and said speed measuring means for starting the operation of the signal a predetermined interval of time prior to arrival of the train at the intersection regardless of the speed of the train, and means controlled by the acceleration-deceleration measuring means to correct the time of starting operation of the signal in proportion to the acceleration or deceleration of the train to assure said predetermined interval of operation when the train is accelerating or decelerating.

BRANKO LAZICH. 

